Extremely high purity phosphorus is required in growing films of phosphorus, polyphosphides and other phosphorus compounds by chemical vapor deposition, sputtering, vacuum deposition and molecular beam deposition for use in semiconductor devices. The P.sub.4 vapor species utilized in these processes has to be extremely pure. Liquid white phosphorus is a convenient source of this species. It is therefore highly desirable to have a source of high purity white phosphorus. However, high purity white phosphorus is not available commercially.